Guide blade fixture in a flow channel of an aircraft gas turbine

Abstract

An arrangement for detachably fixing a guide blade segment that forms part of a transition channel of an aircraft gas turbine comprises high-pressure and low-pressure turbines. The arrangement has a groove-hook-type connection in the front area of the outer platform of the guide blade segment for its radial fixation and at least one pin that penetrates the hook-groove-type connection for securing it against rotation of the guide blade segment.

Description

BACKGROUND AND SUMMARY OF THE INVENTION[0001]This invention relates to an arrangement for fixing a guide blade segment that forms part of a transition channel.[0002]Modern aircraft gas turbines frequently comprise a so-called core engine with a high-pressure turbine having a relatively small diameter, which is arranged downstream from a low-pressure turbine having a relatively large diameter. This creates the necessity of transitioning the ring channel, which extends through the gas turbine and is equipped with guide blades, behind the high-pressure turbine from its small diameter to the large diameter of the low-pressure turbine, which occurs with the aid of a so-called transition channel.[0003]Such engines furthermore have high bypass ratios and low speeds of the low-pressure turbine shaft, which is generally separated in relation to the high-pressure turbine shaft; moreover the urgency exists to design the core engines in an increasingly compact and powerful manner, which leads t...

AI Technical Summary

Benefits of technology

[0009]The design pursuant to the invention has a series of advantages. For example, a simple and safely functioning seal of the guide blade segments on the inside and outside, and thus to the disk area between the high-pressure and low-pressure turbine, is possible through the straight surface contact between the bars and bearing surfaces of the housing and the bearing pedestal. Through the groove-hook-type connection in the front area of the outer platform of the guide blade segment, these are held radially in the turbine housing in a safe and permanent fashion and are fixed in the circumferential direction by means of the pins engaging in the groove-hook-type connection. The bearing area located on the turbine housing for accommodating the guide blade segment can at the same time serve as a bearing area for a channel segment of the transition channel engaging likewise on the bearing surface so that the mounted guide blade segment of the transition channel is a locking element for the channel segment arranged upstream.

[0010]The arrangement pursuant to the invention of the grooves on the groove-hook-type connection on the housing and the arrangement of the hooks on the outside platform part of the channel segment enables a simple and accurate production of these parts, leading to significant weight and cost advantages.

Problems solved by technology

Such engines furthermore have high bypass ratios and low speeds of the low-pressure turbine shaft, which is generally separated in relation to the high-pressure turbine shaft; moreover the urgency exists to design the core engines in an increasingly compact and powerful manner, which leads to increasingly longer axially extending transition channels with greater differences between the radii of the channel cross-sections that need to be taken into consideration.

Hence, no integral, inherently stable guide blade segments exist.

In the area of the guide elements (22, 24, 26, 28), the design is relatively complex as well problematic from a stability point of view.

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